M. Blaskiewicz, J. Brennan, T. Roser, K. Smith, R. Spitz, A. Zaltsman, M. Fujieda, Y. Iwashita, A. Noda, M. Yoshii, Y. Mori, C. Ohmori, Y. Sato
In collaboration with KEK two barrier cavities, each generating 40 kV per turn have been installed in the Brookhaven AGS. Machine studies are described and their implications for high intensity operations are discussed.
{"title":"Barrier cavities in the Brookhaven AGS","authors":"M. Blaskiewicz, J. Brennan, T. Roser, K. Smith, R. Spitz, A. Zaltsman, M. Fujieda, Y. Iwashita, A. Noda, M. Yoshii, Y. Mori, C. Ohmori, Y. Sato","doi":"10.1109/PAC.1999.792659","DOIUrl":"https://doi.org/10.1109/PAC.1999.792659","url":null,"abstract":"In collaboration with KEK two barrier cavities, each generating 40 kV per turn have been installed in the Brookhaven AGS. Machine studies are described and their implications for high intensity operations are discussed.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74638934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
There is a new magnetic alloy called Finemet which has very constant /spl mu/'/sub p/Qf up to /spl sim/2 kG and is very stable at high magnetic flux density and temperature. It may be a good candidate for high-gradient RF cavities. However, it has a rather low quality factor and is therefore very lossy. We compare the pros and cons of Finemet versus the common ferrite, when used in low-energy accelerating cavities, insertion for space-charge compensation, and barrier cavities.
{"title":"Finemet versus ferrite-pros and cons","authors":"K. Ng, Z. Qian","doi":"10.1109/PAC.1999.795384","DOIUrl":"https://doi.org/10.1109/PAC.1999.795384","url":null,"abstract":"There is a new magnetic alloy called Finemet which has very constant /spl mu/'/sub p/Qf up to /spl sim/2 kG and is very stable at high magnetic flux density and temperature. It may be a good candidate for high-gradient RF cavities. However, it has a rather low quality factor and is therefore very lossy. We compare the pros and cons of Finemet versus the common ferrite, when used in low-energy accelerating cavities, insertion for space-charge compensation, and barrier cavities.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75303974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The design of a broad band ultra-low noise ferrite loaded AC beam transformer is presented. It is designed for use in the CERN Antiproton Decelerator (AD), where beams of a few 10/sup 7/ charges must be decelerated from 3.5 GeV/c to 100 MeV/c. It is used in the RF beam-phase loop, and for intensity and bunch shape measurements during deceleration. When the beam is debunched for cooling on magnetic flat tops, the pick-up is used for measurements of intensity and momentum distribution by means of longitudinal Schottky scans. When used as Schottky pick-up, the signal to noise ratio should be better by about 40 dB than the existing stripline based longitudinal Schottky pick-up. The integrated design of pick-up and associated low-noise amplifier is presented.
{"title":"An ultra low noise AC beam transformer for deceleration and diagnostics of low intensity beams","authors":"C. González, F. Pedersen","doi":"10.1109/PAC.1999.795736","DOIUrl":"https://doi.org/10.1109/PAC.1999.795736","url":null,"abstract":"The design of a broad band ultra-low noise ferrite loaded AC beam transformer is presented. It is designed for use in the CERN Antiproton Decelerator (AD), where beams of a few 10/sup 7/ charges must be decelerated from 3.5 GeV/c to 100 MeV/c. It is used in the RF beam-phase loop, and for intensity and bunch shape measurements during deceleration. When the beam is debunched for cooling on magnetic flat tops, the pick-up is used for measurements of intensity and momentum distribution by means of longitudinal Schottky scans. When used as Schottky pick-up, the signal to noise ratio should be better by about 40 dB than the existing stripline based longitudinal Schottky pick-up. The integrated design of pick-up and associated low-noise amplifier is presented.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91130245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Bias, S. Hancock, M. Lindroos, F. Pedersen, S. Koscielniak
A technique for increasing the bunching factor (B/sub f/) is described. Typically in booster-type synchrotrons, it is important to reduce the transverse space-charge tune shift. One means to achieve this is to increase the ratio of average to peak longitudinal charge density. Essentially, the idea is to create hollow bunches by sweeping high-harmonic empty buckets into the particle beam prior to bunching and acceleration. Successful beam experiments are reported with supporting LONG1D simulation studies performed on the CERN PS Booster for both single and dual rf cases. The longitudinally hollow bunches also benefit the receiving ring during the double batch transfer where half of the PS has to wait 1.2 seconds at low energy for the second injection. A 15/sup th/ harmonic rf system was used to form the empty buckets. Simulations show that for the single harmonic case, B/sub f/ is increased from 0.28 to 0.38, and for the dual harmonic one, B/sub f/ is increased from 0.45 to 0.55 (values at 100 MeV). The flattening technique has been tested successfully with the first harmonic to 1 GeV and to 100 MeV for dual harmonic acceleration.
{"title":"New technique for bunch shape flattening","authors":"A. Bias, S. Hancock, M. Lindroos, F. Pedersen, S. Koscielniak","doi":"10.1109/PAC.1999.795647","DOIUrl":"https://doi.org/10.1109/PAC.1999.795647","url":null,"abstract":"A technique for increasing the bunching factor (B/sub f/) is described. Typically in booster-type synchrotrons, it is important to reduce the transverse space-charge tune shift. One means to achieve this is to increase the ratio of average to peak longitudinal charge density. Essentially, the idea is to create hollow bunches by sweeping high-harmonic empty buckets into the particle beam prior to bunching and acceleration. Successful beam experiments are reported with supporting LONG1D simulation studies performed on the CERN PS Booster for both single and dual rf cases. The longitudinally hollow bunches also benefit the receiving ring during the double batch transfer where half of the PS has to wait 1.2 seconds at low energy for the second injection. A 15/sup th/ harmonic rf system was used to form the empty buckets. Simulations show that for the single harmonic case, B/sub f/ is increased from 0.28 to 0.38, and for the dual harmonic one, B/sub f/ is increased from 0.45 to 0.55 (values at 100 MeV). The flattening technique has been tested successfully with the first harmonic to 1 GeV and to 100 MeV for dual harmonic acceleration.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91523783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Crawford, F. Niell, G. Saewert, J. Santucci, A. Sery, A. Shemyakin, V. Shiltsev, D. Wildman, A. Aleksandrov, L. Arapov, G. Kuznetsov, P. Logachov, A. N. Sharapa, B. Skarbo, B. Sukhina
A prototype "electron lens" for the Tevatron beam-beam compensation project is commissioned at Fermilab. We describe the set-up, report results of the first tests of the electron beam, and discuss future plans.
{"title":"Prototype \"electron lens\" set-up for the Tevatron beam-beam compensation","authors":"C. Crawford, F. Niell, G. Saewert, J. Santucci, A. Sery, A. Shemyakin, V. Shiltsev, D. Wildman, A. Aleksandrov, L. Arapov, G. Kuznetsov, P. Logachov, A. N. Sharapa, B. Skarbo, B. Sukhina","doi":"10.1109/PAC.1999.795673","DOIUrl":"https://doi.org/10.1109/PAC.1999.795673","url":null,"abstract":"A prototype \"electron lens\" for the Tevatron beam-beam compensation project is commissioned at Fermilab. We describe the set-up, report results of the first tests of the electron beam, and discuss future plans.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80205518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to enhance the Fermilab hadron research program and to provide a proton source to a future muon storage ring or a muon collider, the study of a new high intensity proton machine called the Proton Driver is being pursued at Fermilab. It would replace the present linac and 8 GeV Booster and produce 20 times the proton intensity as the Booster. This paper gives a status report on a number of design issues of this machine.
{"title":"Status of the Proton Driver study at Fermilab","authors":"W. Chou","doi":"10.1109/PAC.1999.792278","DOIUrl":"https://doi.org/10.1109/PAC.1999.792278","url":null,"abstract":"In order to enhance the Fermilab hadron research program and to provide a proton source to a future muon storage ring or a muon collider, the study of a new high intensity proton machine called the Proton Driver is being pursued at Fermilab. It would replace the present linac and 8 GeV Booster and produce 20 times the proton intensity as the Booster. This paper gives a status report on a number of design issues of this machine.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83420059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The longitudinal profile of an 10 nC electron bunch of a few picoseconds duration will be measured by electro-optic detection of the wakefield. The polarization of a short infrared probe laser pulse (derived from the photocathode excitation laser) is modulated in a LiTaO/sub 3/ crystal by the transient electric field of the bunch. The bunch profile is measured by scanning the delay between the laser and the bunch, and is sensitive to head/tail asymmetries. A singleshot extension of the technique is possible using a longer chirped laser pulse.
{"title":"Picosecond electron bunch length measurement by electro-optic detection of the wakefield","authors":"Michael J. Fitch, A. Melissinos, P. L. Colestock","doi":"10.1109/PAC.1999.794413","DOIUrl":"https://doi.org/10.1109/PAC.1999.794413","url":null,"abstract":"The longitudinal profile of an 10 nC electron bunch of a few picoseconds duration will be measured by electro-optic detection of the wakefield. The polarization of a short infrared probe laser pulse (derived from the photocathode excitation laser) is modulated in a LiTaO/sub 3/ crystal by the transient electric field of the bunch. The bunch profile is measured by scanning the delay between the laser and the bunch, and is sensitive to head/tail asymmetries. A singleshot extension of the technique is possible using a longer chirped laser pulse.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77370543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Afonin, V. Biryukov, V. N. Chepegin, Y. Chesnokov, V. Kotov, V. Terekhov, E. Troyanov, Y. Fedotov
Using channeling in a 5-mm crystal with bending angle of 0.65 mrad, a record high efficiency, over 60%, of particle extraction from the accelerator was achieved. The extracted beam intensity was up to 5.2/spl times/10/sup 11/ protons per spill of /spl sim/0.5 s duration. Also, the first proof-of-principle experiment on 'crystal collimation' was performed where crystal-serving as a scraper-has reduced the radiation level in the accelerator by a factor of two. The measurements agree with Monte Carlo predictions.
{"title":"New projects of crystal extraction at IHEP 70 GeV accelerator","authors":"A. Afonin, V. Biryukov, V. N. Chepegin, Y. Chesnokov, V. Kotov, V. Terekhov, E. Troyanov, Y. Fedotov","doi":"10.1109/PAC.1999.795622","DOIUrl":"https://doi.org/10.1109/PAC.1999.795622","url":null,"abstract":"Using channeling in a 5-mm crystal with bending angle of 0.65 mrad, a record high efficiency, over 60%, of particle extraction from the accelerator was achieved. The extracted beam intensity was up to 5.2/spl times/10/sup 11/ protons per spill of /spl sim/0.5 s duration. Also, the first proof-of-principle experiment on 'crystal collimation' was performed where crystal-serving as a scraper-has reduced the radiation level in the accelerator by a factor of two. The measurements agree with Monte Carlo predictions.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83566629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Very Large Hadron Collider (VLHC) is a superconducting proton-proton collider with approximately 100 TeV cm and approximately 10/sup 34/ s/sup -1/ cm/sup -2/ luminosity. Currently, beam dynamics in this future accelerator is the subject of intensive studies within the framework of the US-wide VLHC R&D program. This presentation summarizes recent developments in the field. Besides general discussion on relevant VLHC parameters, we consider various beam instabilities and ways to avoid them. Finally, we outline possibilities for theoretical and experimental R&D.
超大型强子对撞机(VLHC)是一种超导质子-质子对撞机，其亮度约为100 TeV / cm，光度约为10/sup 34/ s/sup -1/ cm/sup -2/。目前，这台未来加速器的束流动力学是美国大型强子对撞机研发计划框架内深入研究的课题。本报告总结了该领域的最新发展。除了对VLHC的相关参数进行一般性讨论外，我们还考虑了各种波束不稳定性及其避免方法。最后，我们概述了理论和实验研发的可能性。
{"title":"Beam instabilities in Very Large Hadron Collider","authors":"V. Shiltsev, J. Marriner, V. Danilov","doi":"10.1109/PAC.1999.795782","DOIUrl":"https://doi.org/10.1109/PAC.1999.795782","url":null,"abstract":"The Very Large Hadron Collider (VLHC) is a superconducting proton-proton collider with approximately 100 TeV cm and approximately 10/sup 34/ s/sup -1/ cm/sup -2/ luminosity. Currently, beam dynamics in this future accelerator is the subject of intensive studies within the framework of the US-wide VLHC R&D program. This presentation summarizes recent developments in the field. Besides general discussion on relevant VLHC parameters, we consider various beam instabilities and ways to avoid them. Finally, we outline possibilities for theoretical and experimental R&D.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90437057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Thompson, T. Barklow, T. Markiewicz, T. Raubenheimer
A linear collider is determined largely by the beamsstrahlung spectrum. The beammsstrahlung spectrum in turn is sensitive to the design parameters at the interaction point. In this paper we examine the optimization of the luminosity spectrum for discovery and detailed exploration of various physics processes of interest in the NLC, in particular, top and stop pair production, and a class of processes occurring via WW scattering.
{"title":"Optimization of the luminosity spectrum in the NLC","authors":"K. Thompson, T. Barklow, T. Markiewicz, T. Raubenheimer","doi":"10.1109/PAC.1999.792346","DOIUrl":"https://doi.org/10.1109/PAC.1999.792346","url":null,"abstract":"A linear collider is determined largely by the beamsstrahlung spectrum. The beammsstrahlung spectrum in turn is sensitive to the design parameters at the interaction point. In this paper we examine the optimization of the luminosity spectrum for discovery and detailed exploration of various physics processes of interest in the NLC, in particular, top and stop pair production, and a class of processes occurring via WW scattering.","PeriodicalId":20453,"journal":{"name":"Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1999-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84180774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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